This invention relates generally to filtration apparatus and, in particular, to filtration apparatus including filter engagement structure.
Dust collectors are used to filter particulates out of air that is drawn from various sources including fume and ventilation hoods used in industrial applications such as welding and chemical and pharmaceutical
In known dust collectors, the process of replacing a stack of filter cartridges requires the operator to release the mechanical sealing force on a stack of filter cartridges, physically remove the top filter cartridge directly under the top wall or cage plate, and also remove the remaining bottom cartridge stack. The operator then places a clean filter cartridge on the top of the support-base plate and a second clean filter cartridge onto the top of the first clean filter cartridge so that both filter cartridges are sitting end to end in a vertical direction which defines a single stack of cartridges. Once the cartridges are inserted, it becomes necessary to create a seal between the cartridges and between the cartridge top wall or cage plate.
Various devices are known in the art for sealing filter cartridges into position in a dust collector. U.S. Pat. No. 5,599,364 (Hawkins) discloses a parallel pair of filter trays which support the mounting plate of the cylindrical filters thereby supporting the filters themselves. The filter trays interact with support brackets mounted on the partition between the xe2x80x9ccleanxe2x80x9d and xe2x80x9cdirtyxe2x80x9d sections of the dust collector. These support brackets are designed so as to lock the filters snugly against the partition when the trays are slid in one direction, and release the filters when the trays are moved in the opposite direction. A shortcoming of the Hawkins device is that it is not designed to accommodate filters stacked on top of each other, nor does it make it easy to replace a particular filter as it is not easy to access a filter located in the interior of the group of filters supported on a particular pair of trays.
U.S. Pat. No. 4,435,197 (Nijhawan et al.) discloses a baghouse filter in which the partition which mounts the filter bags is formed integrally with the access door of the housing. Such an arrangement allows for the filter bags to be exposed for servicing when the access door is displaced. This arrangement, however, does not allow for a plurality of filters to be stacked in the housing. Furthermore, it requires that the filters be lifted up through the top of the housing, thereby making it more difficult for an operator to access filters that need replacing.
A device that would allow for easy access to, and removal of, used filters as well as assist an operator in applying force to the cartridges in order to generate a seal between the filters and wall or partition surfaces would be an important improvement in the art.
An object of the invention is to provide a filter engagement device that overcomes some of the problems and shortcomings of the prior art.
Another object of the invention is to provide a filter engagement device that mechanically lifts, engages, and holds one or more filter cartridges in a dust collector.
Yet another object of the invention is to provide a filter engagement device that mechanically lifts, engages, and holds a vertically positioned filter cartridge in a dust collector.
Still another object of the invention is to provide a filter engagement device that allows a stack of vertically positioned filter cartridges to be lowered into a xe2x80x9cremovalxe2x80x9d position in a dust collector.
How these and other objects are accomplished will become apparent from the following descriptions and from the drawings.
The invention relates to a dust collector comprising a housing enclosing clean-air and dirty-air chambers and a push, lift or hold-release device provided to engage filter structure within the collector. The collector preferably includes a support base in the housing having a support side and an opposite side, and a contact surface spaced from the support base and facing the support side. A filter is engaged between the support side and the contact surface. The push, lift or hold-release device is provided to secure the filter between a xe2x80x9choldxe2x80x9d position in which the filter is secured in sealed engagement with the support side and the contact surface and a xe2x80x9cremovalxe2x80x9d position in which said device permits the filter to be removed from the housing.
In one embodiment of the invention, the contact surface includes an opening in communication with a clean-air chamber, the support base has an outer edge and a plurality of guide pins are located around the outer edge such that a filter positioned on the support base between the guide pins is centered with respect to the opening in the contact surface.
In another embodiment of the invention, the push device is further comprised of an engage-pedal arm having a first length and a push member, which preferably is a cam-follower arm having a second length which is shorter than the first length. The cam-follower arm is attached to the engage-pedal arm. In a specific version of the embodiment, a disengage-pivot arm having a horizontal stud attached thereto is adjacent the engage-pedal arm. In a more specific version, the cam-follower arm includes first and second holes. A hub having a bore therein is placed in relationship to the support base. A hub-guide pin extends into the hub and attaches to the housing. A stud is attached to the hub and the cam-follower arm is connected to the stud such that the stud is positioned through the cam-follower arm first hole. The stud positioned through the cam-follower arm first hole acts as the main-pivot point for the lift.
In still another embodiment of the invention, at least two filters, each having a first and second end, are stacked in the housing such that the second end of the first filter is engaged with the first end of the second filter. The push device seals the second end of the first filter to the first end of the second filter and the second end of the second filter to the contact surface.
In a preferred embodiment of the invention, the dust collector comprises a housing that encloses clean-air and dirty-air chambers. A support base having an upper side and an underside is located within the housing. A wall surface is spaced from the support base and faces the upper side thereof An elongate annular filter is vertically engaged between the upper side of the support base and the wall surface while a lift device secured with respect to the housing engages the underside of the support base such that the filter is sandwiched and sealed between the support base and the wall surface.
In another embodiment of this invention, the support base has an outer edge and a plurality of guide pins are located around the outer edge to locate the filter on the support base.
In still another embodiment of the invention, the lift device is further comprised of an engage-pedal arm having a first length and a cam-follower arm, which is shorter in length than the engage-pedal arm, connected to the engage-pedal arm. In a more specific version of this preferred embodiment, a disengage-pivot arm is adjacent to the engage-pedal arm. The disengage-pivot arm includes a horizontal stud attached thereto.
In a more specific version of such embodiment, the cam-follower arm includes a first and a second hole. A hub having a bore therein is placed in relationship to the support base and a hub-guide pin extends from the hub and attaches to the housing. The embodiment includes a stud attached to the hub which allows the cam-follower arm to be connected to the stud in such a manner that the stud positioned in the cam-follower arm first hole acts as the main-pivot point for the lift device.
In the more preferred embodiment of the invention, at least two filters, each having a first and second end, are stacked in the housing. In such an arrangement, the first and second ends of the second filter and the second end of the first filter are open so as to allow the air that has been filtered to pass into the clean-air chamber. In one version of this embodiment, the first end of the first filter is enclosed by a cover. In such embodiment, the second end of the first filter is engaged with the first end of the second filter in such a manner that, once engaged, the lift device seals the second end of the first filter to the first end of the second filter and the second end of the second filter to the contact surface. In a more particular version of this embodiment, the second end of the second filter is also open. In this version, engagement of the lift device would result in the sealing of the first end of the first filter with the support base.